Jensen in U.K. Patent Application No. 2,099,308 discloses a wound drainage device in the form of a flexible pouch having top and bottom walls and pleated side walls that allow the top wall to be lifted a limited distance without transmitting appreciable lifting forces to the bottom wall when the bottom wall is surgically apertured and secured about a wound site. The top wall includes an access opening having a flanged locking ring of flexible plastics extending thereabout. A removable closure cap is attached to the access opening, the cap having a flat rim of flexible plastics with circumferential locking ribs releasably and sealingly engaging a series of mating ribs provided by the flanged portion of the ring.
Nordby et al. in U.S. Pat. No. Re. 29,319 disclose a wound drainage system which includes a drainable pouch having an apertured wall provided with an annular adhesive patch for securing the pouch to a patient in an area surrounding the wound site. The opposite wall of the pouch is provided with an access opening, and a transparent cap is adhesively secured to the pouch about that opening. When access to the wound is required for surgical examination, drain adjustment, wound treatment, or any other reason, the pressure-sensitive adhesive seal between the cap and pouch is broken and the cap is temporarily removed.
Other wound drainage and treatment devices are disclosed by Westaby et al. in British Pat. No. 1,549,756, Harvey in U.S. Pat. No. 3,568,675, Barbieri in U.S. Pat. No. 874,387, Warnecke et al. in U.S. Pat. No. 4,023,569, Stivala in U.S. Pat. No. 4,224,941, and Adair in U.S. Pat. No. 4,250,882.